Collaborative Research: Optimization of metal attenuation in biologically-active remediation systems

合作研究：生物活性修复系统中金属衰减的优化

• 批准号: 1336496
• 负责人: Colleen Hansel
• 金额: $ 18.56万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2016-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1336496&HistoricalAwards=false
• 关键词: Collaborative; Research; Optimization; metal; attenuation

CBET 1336496/1336247Colleen Hansel/Cara SantelliWoods Hole Ocean Inst. /Smithsonian InstututionCoal-mining activities have resulted in worldwide environmental pollution due to the production of acidic, metal-rich waters that damage entire ecosystems and contaminate water supplies compromising public health. Coal mine drainage (CMD) throughout the Appalachian region contains particularly elevated concentrations of dissolved manganese (Mn), that at such high levels may lead to neurological disorders. One of the most promising and economically feasible approaches to treat metal-laden CMD containing elevated Mn are biologically active limestone treatment beds. Limestone is used to raise the pH of the contaminated waters to promote growth of microorganisms that can transform (via oxidation reactions) soluble Mn to solid Mn oxide minerals that are subsequently retained within the treatment beds. Formation of these minerals effectively removes Mn from the water and also produces a substrate that serves as a water treatment filter, effectively removing additional contaminants, such as cobalt, zinc, and nickel, from CMD. At this time, the successful removal of Mn and other metal contaminants from mine waters is highly variable and as low as 20% removal of Mn in some systems in Pennsylvania. Success of these treatment systems is currently limited by an insufficient knowledge of the individual and collective activities of microbial populations and the optimal conditions for biologically mediated Mn oxide formation. This research will address these knowledge gaps by simulating limestone treatment systems under controlled laboratory conditions to better establish the most effective biogeochemical conditions for stimulating both microbial growth and subsequent metal attenuation in CMD treatment systems. Specifically, the project will first identify the most effective microbial species and nutrient conditions (e.g., organic carbon and nitrogen composition) stimulating optimal Mn oxide formation by pure and mixed laboratory cultures of bacteria, fungi, and algae previously isolated from CMD treatment systems. These vital nutrient and microbiological conditions will then be employed and tested in laboratory-simulated treatment systems to further optimize Mn removal and precipitation efficiencies by complex microbial assemblages and the activity of key microbial species. Throughout the experiments, the microbial population structure and community interactions that impact Mn removal and Mn oxide formation will be identified. The composition and stability of the biologically precipitated Mn oxide minerals and their efficacy in removing metal contaminants will also be assessed. The development of successful and cost-effective approaches for cleaning contaminated environments and water supplies is an immediate priority. This project will answer key scientific questions limiting the success of biologically stimulated treatment processes and optimize low-cost, green technologies currently employed throughout the world in an attempt to clean environments devastated by mine drainage. Essential knowledge gained by this project will be conveyed to scientists, engineers, educators, and government regulators for direct application to limestone treatment systems currently being used at hundreds of sites in Appalachia to treat coal mine drainage. An equally important goal of this project is to educate future generations and the general public on the causes, effects, and solutions to mine drainage. The PIs will integrate this research into two outreach activities, including (1) high school science teacher internships to aid in the development of new curricula that will engage underrepresented students in STEM fields and introduce them to green technologies used to treat environmental pollution and (2) informal presentations and inquiry-based learning exercises at the National Museum of Natural History, Smithsonian Institution, to communicate science activities and products to the general public and provide opportunities for visitors to ask questions and personally interact with the scientists.

CBET 1336496/1336247科琳·汉塞尔/卡拉·桑特利伍兹霍尔海洋研究所/史密森尼研究所煤炭开采活动由于产生酸性、富含金属的沃茨，破坏了整个生态系统，污染了供水，损害了公众健康，导致了全球环境污染。整个阿巴拉契亚地区的煤矿排水（CMD）含有特别高浓度的溶解锰（Mn），在如此高的水平下可能导致神经系统疾病。生物活性石灰石处理床是处理含高Mn的负载金属CMD的最有前途和经济可行的方法之一。石灰石用于提高污染的沃茨的pH以促进微生物的生长，所述微生物可以将可溶性Mn转化（通过氧化反应）为固体Mn氧化物矿物，所述固体Mn氧化物矿物随后保留在处理床内。 这些矿物质的形成有效地从水中去除Mn，并且还产生用作水处理过滤器的基材，有效地从CMD中去除额外的污染物，例如钴，锌和镍。 此时，从矿井沃茨中成功去除Mn和其他金属污染物的情况是高度可变的，在宾夕法尼亚州的一些系统中Mn的去除率低至20%。这些处理系统的成功目前受到对微生物种群的个体和集体活动以及生物介导的氧化锰形成的最佳条件的不充分了解的限制。 本研究将通过在受控实验室条件下模拟石灰石处理系统来解决这些知识空白，以更好地建立最有效的生物地球化学条件，以刺激微生物生长和随后的CMD处理系统中的金属衰减。具体而言，该项目将首先确定最有效的微生物种类和营养条件（例如，有机碳和氮组成），通过先前从CMD处理系统分离的细菌、真菌和藻类的纯的和混合的实验室培养物刺激最佳的氧化锰形成。这些重要的营养和微生物条件，然后将采用和实验室模拟处理系统进行测试，以进一步优化锰的去除和沉淀效率的复杂的微生物组合和关键微生物物种的活性。在整个实验过程中，将确定影响锰去除和氧化锰形成的微生物种群结构和群落相互作用。还将评估生物沉淀的氧化锰矿物的组成和稳定性及其在去除金属污染物方面的功效。 制定成功和具有成本效益的方法来清洁受污染的环境和供水是当务之急。该项目将回答限制生物刺激处理过程成功的关键科学问题，并优化目前世界各地为清洁被矿井排水破坏的环境而采用的低成本、绿色技术。 该项目获得的基本知识将传达给科学家，工程师，教育工作者和政府监管机构，直接应用于目前在阿巴拉契亚数百个地点使用的石灰石处理系统，以处理煤矿排水。 该项目的一个同样重要的目标是教育后代和公众了解矿井排水的原因、影响和解决办法。 PI将把这项研究纳入两项外展活动，包括（1）高中科学教师实习，以帮助开发新课程，使STEM领域代表性不足的学生参与进来，并向他们介绍用于处理环境污染的绿色技术，以及（2）在史密森尼学会国家自然历史博物馆进行非正式演讲和基于探究的学习练习，向公众宣传科学活动和产品，并为参观者提供提问和与科学家亲自互动的机会。